Field of the Invention
The present invention relates to a display panel and a display device including the same and in particular, relates to suppression of a wire breakage and the like in a display panel.
Description of the Background Art
Display devices are widely adopted as user interfaces in various fields, and liquid crystal display devices using liquid crystals are mainstream of current display devices. A liquid crystal display device is provided with a thin film transistor (TFT) array substrate, a counter substrate disposed to face the TFT array substrate, and a liquid crystal layer provided therebetween.
In the TFT array substrate, a display region for displaying video and a circuit component mounting region on which circuit components are mounted are defined. The counter substrate of the liquid crystal display device is cut to expose the circuit component mounting region.
In a cutting process for exposing the circuit component mounting region, a sharp foreign matter is generated. Particularly, in a case of using a glass plate as the substrate, a foreign matter that is sharp and firm is generated. If such the foreign matter comes into contact with (adheres to) a surface of the TFT array substrate and an external force is applied to the foreign matter, a protective film (insulating film) and a wiring of the TFT array substrate may be damaged in some cases. Moreover, if an offcut formed in the cutting process comes into contact with the surface of the TFT array substrate, the protective film and consequently the wiring of the TFT array substrate may also be damaged in some cases.
As a result, a wiring is broken and a malfunction such as a line defect of the display occurs. In addition, a product separated in an inspection during a manufacturing process due to a line defect such as a wire breakage is eliminated, so that the wire breakage is one of the factors that reduce yields of products. Moreover, in the case where a product with damage which does not cause a wire breakage during the manufacturing process passes the inspection, there is a possibility that a line defect may occur after shipment.
About this, Japanese Patent Application Laid-Open No. 2010-230885 discloses a technique for suppressing an impact on the TFT array substrate at the time of cutting the counter substrate. Specifically, Japanese Patent Application Laid-Open No. 2010-230885 discloses the technique capable of reducing an impact on the wiring disposed as a lower layer and preventing a wire breakage by forming a pattern in a floating potential state on the wiring connecting the display region and the circuit component mounting region.
In the configuration of Japanese Patent Application Laid-Open No. 2010-230885, the pattern serving as a shock absorbing layer is further formed on a plurality of wirings, respectively, so that the shock absorbing layer reduces the impact on the wirings as the lower layer. Unfortunately, the entire film thickness of a laminated film (such as the shock absorbing layer and insulating layer) on the wirings is significantly thick, and thus there is a higher probability to come into contact with a foreign matter, whereby there is a possibility that the laminated film is destroyed and the wirings are exposed. When the wirings are exposed, they become susceptible to moisture and the like from the outside, and there is a higher possibility that a malfunction such as a wire breakage occurs because electric corrosion is induced as the wirings are energized.